This package provides a powerful yet simple graphical tool available in the field of psychometrics is the Wright Map (also known as item maps or item-person maps), which presents the location of both respondents and items on the same scale. Wright Maps are commonly used to present the results of dichotomous or polytomous item response models. The WrightMap
package provides functions to create these plots from item parameters and person estimates stored as R objects. Although the package can be used in conjunction with any software used to estimate the IRT model (e.g. TAM', mirt', eRm
or IRToys in R', or Stata', Mplus', etc.), WrightMap
features special integration with ConQuest
to facilitate reading and plotting its output directly.The wrightMap
function creates Wright Maps based on person estimates and item parameters produced by an item response analysis. The CQmodel function reads output files created using ConQuest
software and creates a set of data frames for easy data manipulation, bundled in a CQmodel object. The wrightMap
function can take a CQmodel object as input or it can be used to create Wright Maps directly from data frames of person and item parameters.